Ionosphere

Abstract

The ionospheric structure of the major planets has been measured since 1973, using the technique of radio occultation (Chap. II) from Pioneer and Voyager spacecrafts. The principal difference between the Pioneer and the Voyager measurements is that the former were carried out using a single frequency oscillator (S-band at 2.293 GHz or 13 cm-λ), while the latter employed dual frequency mode (S-band, and X-band at 8.6 GHz or 3.6 cm-λ).